Influence of Asymmetric Monotonic Hot Rolling on Microstructures and Mechanical Property of Microalloyed Steel  

作　　者：李建平 刘珍光 BAI Xiaolei LI Ping 

机构地区：[1]The State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, China [2]School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China [3]College of Chemistry, Jilin University and MacDiarmid Laboratory, Changehun 130021, China

出　　处：《Journal of Wuhan University of Technology(Materials Science)》2017年第2期422-429,共8页武汉理工大学学报（材料科学英文版）

基　　金：Funded by the National Key Technology Research and Development Program of the Ministry of Science and Technology of China during the“12th Five-Year Plan”(No.2011BAE25B03);the National Natural Science Foundation of China(No.51274063);the National High Technology Research and Development Program of China(No.2015AA03A501)

摘　　要：For refining grain and obtaining excellent properties, the experiments of asymmetric and symmetric monotonic hot rolling were carried out to investigate the role of shear strain on the microstructures and mechanical properties of V-microalloyed steel. The study demonstrates that the gradient ferrite distribution and dispersive pearlite through the sheet thickness are observed in asymmetric rolled specimen, and the homogeneous microstructure with ferrite and large pearlite is found in symmetric rolled specimen. The average grain size in asymmetric rolled specimen is smaller than the one in symmetric rolled specimen. The styles of precipitate morphology in asymmetric rolled specimen are random precipitate and obvious interphase precipitate, while the ones in symmetric rolled specimen are random precipitate and unobvious interphase precipitate. The additional shear strain results in the microstructure difference between asymmetric rolled specimen and symmetric rolled specimen. The impact energy of asymmetric rolled specimen, 58 J, is more than the one of symmetric rolled specimen, 48 J. Both deflection-energy curve and fracture morphology show that the fracture style of asymmetric rolled specimen is ductile, and the ones of symmetric rolled specimen are brittle and ductile.For refining grain and obtaining excellent properties, the experiments of asymmetric and symmetric monotonic hot rolling were carried out to investigate the role of shear strain on the microstructures and mechanical properties of V-microalloyed steel. The study demonstrates that the gradient ferrite distribution and dispersive pearlite through the sheet thickness are observed in asymmetric rolled specimen, and the homogeneous microstructure with ferrite and large pearlite is found in symmetric rolled specimen. The average grain size in asymmetric rolled specimen is smaller than the one in symmetric rolled specimen. The styles of precipitate morphology in asymmetric rolled specimen are random precipitate and obvious interphase precipitate, while the ones in symmetric rolled specimen are random precipitate and unobvious interphase precipitate. The additional shear strain results in the microstructure difference between asymmetric rolled specimen and symmetric rolled specimen. The impact energy of asymmetric rolled specimen, 58 J, is more than the one of symmetric rolled specimen, 48 J. Both deflection-energy curve and fracture morphology show that the fracture style of asymmetric rolled specimen is ductile, and the ones of symmetric rolled specimen are brittle and ductile.

关 键 词：asymmetric rolling microstructure shear strain vanadium microalloyed steel 

分 类 号：TG142.1[一般工业技术—材料科学与工程] TG335.11[金属学及工艺—金属材料]